Is it just me, or do large hammerheads (specifically scalloped and great hammerheads) seem to be relatively rare in captivity compared to certain other sharks like, say, sand tigers or blacktips? I can’t imagine it being a welfare issue, because the aquariums that do keep them seem to maintain them just fine. And it certainly can’t be a demand issue, since hammerheads are some of the most famous sharks of all. Anyone have any theories why?
In the past they tended to suddenly die, and you have to design very large tanks with no corners for them. They are definitely harder to keep than sand tigers and blacktip reef sharks. That said, I have seen both scalloped and great hammerheads at aquariums. The former is somewhat common in Asia, and I recommend Sentosa SEA Aquarium for seeing them (there are 2 enormous tanks with scalloped hammerheads). Osaka Kaiyukan is also a great place to see scalloped hammerheads from multiple angles. As for great hammerheads, I know Adventure Aquarium in New Jersey has one, and I saw a pair in an outdoor lagoon at Atlantis Paradise Island, Bahamas.
As RatioTile said its a space issue as Hammerheads typically are migratory meaning they need very large tanks. This is also part of the reason why Leatherback Sea Turtles and Great Whites can't be kept in an aquarium. Luckily Scalloped and Great Hammers don't travel great lengths every day and can find peace in staying in one area.
That said mortality rates with Scalloped Hammerheads are still high in many aquariums, together with them being listed as endangered on the IUCN red list, will make enough zoos less keen to go for them...
Nausicaa in Boulogne sur Mer imported 30+ young scalloped hamerheads. They all died. Burgers Zoo imported 1.2 scalloped hamerheads, 2 died almost as soon as they arrived. The last one died after 10 years. Den Blå planet has imported 10 scalloped hamerheads. Don't know the current status. The aquarium in Paris has or had 3 scalloped hamerheads
The Osaka Aquarium has large Hammerheads, so does the Tokyo Sea Life Park, but theirs are much smaller, maybe 70ish cm tops. They seem to have enough room currently, but their tank is far too small for an adult, and contains species that could be potential prey for an adult (Cownose Rays and Indian Mackerel(?)), so they will likely be moved to a larger tank or released once they grow too large.
I don't really have any theories beyond what's already been stated, but I do know Georgia Aquarium used to have great hammerheads in the Ocean Voyager exhibit, and I'm pretty sure, although not 100 percent, that they're getting them back for the new shark gallery said to open in the fall.
Point Defiance has scalloped hammerheads in their Baja Bay tank. It’s a pretty large tank with no sharp corners and the sharks seem to be doing great. It does mean that a lot of fish tend to stay near the bottom though instead of straying up to where the sharks are. They’re very popular with visitors because it’s the only place in this area that displays them.
What husbandry and housing criteria are critical for hammerheads to do well in a larger aquarium tank? What makes them so sensitive to some captivity exhibitory?
Hammerheads are mentionned on the website for the new shark tank : Expansion 2020 - Georgia Aquarium I visited Biarritz Aquarium (Musée de la Mer- France) last week and saw there was a scalloped hammerhead shark remaining (on the two presented at the opening of the 2011 expansion). I don't know the situation in Paris Aquarium. The scalloped hammerhead sharks are still mentionned on the website but I couldn't find a recent picture of them (on the web, Faceboook...).
